This invention relates generally to processor-based systems and particularly to techniques for providing user inputs in those systems.
A number of processor-based systems, such as web tablets, include no keyboard. For example, many devices use a touch screen, a mouse, or pen as the input device, avoiding the need for a keyboard that takes up more space. However each of these input devices generally needs an operating system in order to receive user inputs.
In some cases, the inability to provide inputs prior to booting of the operating system may create a problem. For example, it may be desirable to require the user to enter a password before actually booting the operating system. Once the operating system is booted, the user may be more able to hack the system in order to gain access without a password. Thus it may be advantageous to require entry of a password or other identifier before booting the system.
As another example, it may be desirable for the user to provide certain information to the system, such as hardware settings, prior to actually booting the system. In other words it may be desirable to enable the input of setting information without requiring that the operating system be booted. Examples of machine setup information may be to convert the system from a universal serial bus (USB) to a PS-2 system, to provide different graphics, or to provide a different hard drive.
Of course in systems without a keyboard, there is no way to provide information prior to the time the operating system has booted. Before operating system boot or in the pre-boot phase, the input devices are incapacitated since they require a functioning operating system.
Therefore, there is a need for a way to receive inputs in processor-based systems in the pre-boot phase.